There are known steering assistance systems which, when the steering wheel is turned and the vehicle is moving, return at said steering wheel, in particular via the steering assistance motor, a return force which tends to spontaneously return said steering wheel toward its neutral central position, and this in order to provide the driver with a better feeling of the running conditions.
If returning such a return force is generally satisfactory, by contributing to improve the driving comfort and safety, it may nevertheless suffer from some limitations.
Indeed, the inventors have observed that the known systems might sometimes be caught out, in some situations in which the natural centering phenomenon tends to be alleviated.
This may in particular happen within propulsion vehicles which have a rear-mounted engine, and the steerable front axle of which thus tends to be less solicited, which makes the steering less prone to the spontaneous centering phenomenon.
If such a lack of centering force can be in part compensated, in the steady state, by the caster effect of the front axle, when the latter exhibits a positive caster angle, by steering wheel return common strategies, this does not hold true in the acceleration phase, because of the additional dynamic lightening that said front axle undergoes due to the acceleration.
The sensations of the driver, and more globally the driving assistance, may then be more or less distorted, to the possible detriment of the control of the behavior of the vehicle.